Krzysztof Pawlaczyk

IL-17 Stimulates Intraperitoneal Neutrophil Infiltration Through the Release of GROα Chemokine from Mesothelial Cells

IL-17 is a newly discovered cytokine implicated in the regulation of hemopoiesis and inflammation. Because IL-17 production is restricted to activated T lymphocytes, the effects exerted by IL-17 may help one to understand the contribution of T cells to the inflammatory response. We investigated the role of IL-17 in leukocyte recruitment into the peritoneal cavity. Leukocyte infiltration in vivo was assessed in BALB/Cj mice. Effects of IL-17 on chemokine generation in vitro were examined in human peritoneal mesothelial cells (HPMC). Administration of IL-17 i.p. resulted in a selective recruitment of neutrophils into the peritoneum and increased levels of KC chemokine (murine homologue of human growth-related oncogene α (GROα). Pretreatment with anti-KC Ab significantly reduced the IL-17-driven neutrophil accumulation. Primary cultures of HPMC expressed IL-17 receptor mRNA. Exposure of HPMC to IL-17 led to a dose- and time-dependent induction of GROα mRNA and protein. Combination of IL-17 together with TNF-α resulted in an increased stability of GROα mRNA and synergistic release of GROα protein. Anti-IL-17 Ab blocked the effects of IL-17 in vitro and in vivo. IL-17 is capable of selectively recruiting neutrophils into the peritoneal cavity via the release of neutrophil-specific chemokines from the peritoneal mesothelium.

The Role of the TGF/Smad Signaling Pathway in Peritoneal Fibrosis Induced by Peritoneal Dialysis Solutions

Background: Peritoneal dialysis (PD) solutions contribute to peritoneal membrane damage. We investigated how conventional and biocompatible PD solutions with different glucose concentrations affect morphological and functional signs of peritoneal fibrosis as well as the TGF-β1/Smad signaling pathway in a chronic PD rat model. Methods: Non-uremic male Wistar rats (n = 28) were dialyzed thrice daily for 28 days with 20 ml of a conventional solution (Dianeal® 1.36%, D1, or 3.86%, D3) or a biocompatible solution (Physioneal® 1.36%, P1, or 3.86%, P3). A peritoneal equilibration test was performed. Six rats without dialysis served as controls. Results: The use of conventional solutions, particularly D3, resulted in expansion of the submesothelial compact zone, loss of mesothelial cell layer integrity, hypercellularity, accumulation of collagen I, increased vessel numbers and increased TGF-β1/Smad expression, but this did not significantly change fluid and solute peritoneal transport characteristics. In comparison with D1 and D3, the use of P1 and P3 was associated with less TGF-β1/Smad expression and less expansion of the submesothelial cell layer. Conclusions: Our findings indicate that biocompatible solutions with less glucose may decrease the rate of peritoneal fibrosis. The TGF-β1/Smad pathway is stimulated by PD solutions, representing a plausible pathophysiological mechanism.

Peroxisome Proliferator-Activated Receptor-γ Agonists Diminish Peritoneal Functional and Morphological Changes Induced by Bioincompatible Peritoneal Dialysis Solution

Background: To evaluate if peroxisome proliferator-activated receptor-γ (PPAR-γ) agonists have a potential protective effect on the peritoneum changes induced by bioincompatible peritoneal dialysis (PD) solution in vivo. Methods: Male Wistar rats were dialyzed three times daily for 28 days with 1.36% Dianeal® (two groups: with (D+R) or without (D) rosiglitazone) or 1.36% Physioneal® (two groups: with (P+R) or without (P) rosiglitazone). Peritoneal transport of fluid and small solutes was assessed. Nine rats that did not receive dialysis served as controls. Results: Significant morphological changes were found in the D group compared with controls. Additional use of rosiglitazone in the D+R group resulted in less morphological changes and expression of collagen I as well as an increased drainage volume. The expression of VEGF was inhibited by rosiglitazone while no apparent effect was found regarding TGF/Smad pathway. Conclusions: The addition of rosiglitazone to standard dialysis fluids can maintain the peritoneal morphology and increase ultrafiltration in a PD rat model.

Animal Models of Peritoneal Dialysis: Thirty Years of Our Own Experience

Experimental animal models improve our understanding of technical problems in peritoneal dialysis PD, and such studies contribute to solving crucial clinical problems. We established an acute and chronic PD model in nonuremic and uremic rats. We observed that kinetics of PD in rats change as the animals are aging, and this effect is due not only to an increasing peritoneal surface area, but also to changes in the permeability of the peritoneum. Changes of the peritoneal permeability seen during chronic PD in rats are comparable to results obtained in humans treated with PD. Effluent dialysate can be drained repeatedly to measure concentration of various bioactive molecules and to correlate the results with the peritoneal permeability. Additionally we can study in in vitro conditions properties of the effluent dialysate on cultured peritoneal mesothelial cells or fibroblasts. We can evaluate acute and chronic effect of various additives to the dialysis fluid on function and permeability of the peritoneum. Results from such study are even more relevant to the clinical scenario when experiments are performed in uremic rats. Our experimental animal PD model not only helps to understand the pathophysiology of PD but also can be used for testing biocompatibility of new PD fluids.

EFFECTS OF HYALURONAN USED AS A SUPPLEMENT IN PERITONEAL DIALYSIS SOLUTIONS

ABSTRACT Hyaluronan present in the peritoneal cavity is removed during the course of peritoneal dialysis. The addition of hyaluronan to dialysis fluids has been proposed as a means to improve peritoneal transport functions and to protect the peritoneal membrane during peritoneal dialysis. Studies in rats have examined the effect of hyaluronan, added to dialysis solutions, on peritoneal permeability, inflammation and morphology. Addition of 10 mg/dL high-molecular weight (hmw) hyaluronan (m.w. 1.8-2.4 × 10 6 D) to the dialysis solution caused significant improvements in fluid and solute transport. Net ultrafiltration of water across the peritoneum increased, whereas the membranes permeability to protein declined. During an eight hour dwell in the peritoneal cavity, about 25% of the administered hyaluronan was absorbed, and concentrations in the peritoneal interstitium and in blood increased significantly. Absorbed hyaluronan was rapidly metabolised and, was not affected by the uremic status of the animal. Hyaluronan reduced the acute intraperitoneal inflammation induced by the initiation of peritoneal dialysis and the surgical procedure. In rats exposed to dialysis solution supplemented with hyaluronan (10 mg/dL) for one month, the interstitial connective tissue in the peritoneal membrane was less thickened than that of control rats, and the membrane had a lower permeability to protein and reduced hydraulic conductivity. potentially helping to promote the removal of water during dialysis. Thus, supplementation of peritoneal dialysis solutions with hyaluronan may improve peritoneal transport and fluid removal while helping to reduce peritoneal inflammation caused by the dialysis procedure.

Dialysis vintage stratified comparison of body composition, hydration and nutritional state in peritoneal dialysis and hemodialysis patients

Introduction Body mass decomposition and hydration state imbalances affect patients on maintenance dialysis. We compared body composition, hydration and nutritional state of patients on peritoneal dialysis (PD) and hemodialysis (HD) based on dialysis vintage (DV). Material and methods Three hundred and fifty-nine prevalent patients on HD (n = 301) and PD (n = 58) were divided into 3 subgroups depending on DV: < 2 years HD (n = 41) and PD (n = 28), 2–4 years HD (n = 111) and PD (n = 17), > 4 years HD (n = 149) and PD (n = 13). Bioimpedance analysis delivered data including overhydration (OH), Lean (LTM) and adipose lipids mass (FAT). Other measurements included daily diuresis (DD), subjective global assessment (SGA) and serum albumin (alb), C-reactive protein (CRP) and total cholesterol (TChol), and hemoglobin (Hb). Results Dialysis vintage < 2 years. Hemodialysis patients were older (65.5 ±18.5 vs. 50.9 ±17.1; p < 0.01) with a higher mortality (28 vs. 1; p < 0.01) and OH (8.0 ±4.3 vs. 1.6 ±3.1; p < 0.001). Hemoglobin (10.6 ±1.5 vs. 11.8 ±1.7; p < 0.05), TChol (180.2 ±47.0 vs. 211.7 ±46.3; p < 0.05), DD (871 ±729 vs. 1695 ±960; p < 0.001) and LTM (46.5 ±12.9 vs. 53.8 ±14.4; p < 0.05) were lower on HD. Dialysis vintage 2–4 years: when compared to PD, HD patients had higher OH (11.7 ±5.9 vs. 2.1 ±3.2; p < 0.001) and lower Hb (10.8 ±1.5 vs. 11.9 ±1.4; p < 0.01). Dialysis vintage > 4 years: compared to PD, HD patients had higher LTM (44.3 ±11.7 vs. 38.6 ±7.9; p < 0.05) and lower FAT (34.4 ±11.1 vs. 42.8 ±6.4; p < 0.01). Conclusions Dialysis patients’ body composition depends on dialysis modality and DV. Dialysis vintage < 2 years is associated with better hydration, nutritional state, and survival in PD patients, but longer DV reduces these benefits. Dialysis vintage > 4 years associated with similar hydration and mortality in both PD and HD while body composition was better on HD.

The importance of hypoalbuminemiain peritoneal dialysis patients: Impact of gender

BACKGROUND High mortality in peritoneal dialysis (PD) patients is associated with the presence of nontraditional cardiovascular risk factors, such as malnutrition. However, hypoalbuminemia in patients undergoing PD may have gender-dependent consequences. OBJECTIVES The aim of the study was to evaluate the relationship between hypoalbuminemia, overhydration (OH), inflammation, and cardiovascular risk, depending on gender. MATERIAL AND METHODS The group studied consisted of 54 PD patients: 26 male (mean age: 59 ±19 years) and 28 female (mean age: 52 ±15 years) patients. Serum albumin levels were measured routinely by the hospital central laboratory. The degree of OH was assessed by bioelectrical impedance analysis (BIA). Serum concentrations of C-reactive protein (CRP) and interleukin (IL)-6 were measured as inflammatory markers. Levels of N-terminal prohormone of brain natriuretic peptide (NT-proBNP) and troponin T (TnT) were used to assess cardiovascular risk. RESULTS Median serum albumin concentration was 3.9 g/dL (3.6-4.2 g/dL). Both genders were comparable regarding most parameters except body weight (79 ±16 kg vs 67 ±16 kg; p = 0.009), but no differences were observed in body mass index (BMI) (26.3 ±5.0 kg/m2 vs 26.2 ±5.9 kg/m2; non significant (NS)). There was also no difference in the prevalence of hypoalbuminemia between female and male PD patients (23% vs 21%; NS). In females, low serum albumin concentrations were associated with OH, inflammation and cardiovascular risk, while in males serum albumin levels correlated with the parameters of dialysis and cardiovascular risk. CONCLUSIONS The impact of hypoalbuminemia may be gender-dependent. It seems that hypoalbuminemia is more important for female patients. It is also possible that different mechanisms regulate serum albumin concentration in female and male PD patients.

Higher Serum Hepatocyte Growth Factor Concentration is Associated with Better Preservation of GFR in Hemodialysis Patients

Background/Aims: Hemodialysis induces an intravascular inflammatory reaction which may further deteriorate renal function. We studied changes of serum interleukin 6 (IL6) and hepatocyte growth factor (HGF) concentrations during dialysis sessions, and at 12 month intervals. The synthesis of these cytokines in arterial endothelial cells in the presence of serum obtained from dialyzed patients was studied. Changes of the inflammatory reaction during 12 months of treatment were correlated with GFR. Methods: The study was performed on a group of 30 uremic patients treated with hemodialysis. Serum samples were collected before the start of dialysis, 15 minutes, and 4 hours later, when the session was finished. Serum levels of IL6 and HGF were measured with ELISA, as was the effect of serum samples on the synthesis of these cytokines in arterial endothelial cells. Results: At baseline hemodialysis induced an increase of serum IL6 (+10%) and HGF (+164%) levels at the end of the session. After 12 months of treatment predialysis serum IL 6 level was increased as compared to the beginning of the study (+22%), but no change in serum HGF level was observed. At that time the dialysis-induced rise of serum IL6 level was stronger than at the start (+18%), but the observed effect for HGF was weaker (+116%). An inverse correlation was observed between the dialysis-induced increase of HGF level and decrease of GFR after 12 months of study. The same relation was seen for HGF synthesis in the endothelium, but opposite for IL6 synthesis in the endothelium. Conclusions: We found that a higher HGF serum level during hemodialysis treatment is associated with a slower loss of residual renal function.

The polymorphism of the ACE gene affects left ventricular hypertrophy and causes disturbances in left ventricular systolic/diastolic function in patients with autosomal dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) is one of the most frequently occurring autosomal diseases inherited in the dominant manner. Due to this, lesions in the cardiovascular system of ADPKD patients have caught the attention of clinical investigators worldwide. The aim of the study was to analyse cardiovascular complications in ADPKD patients with a focus on left ventricular hypertrophy (LVH) and selected components of its systolic/diastolic function based on echocardiography. The study was conducted on 55 patients with ADPKD (24 males, 31 females), subdivided into three groups according to the stage of chronic kidney disease (CKD). The patient group with ADPKD and ESRD (group C) manifested an increased incidence of the D allele as compared to group A and group B (χ 2 = 4.217, P = 0.04). In all ADPKD patients with the DD genotype, left ventricular mass (LVM), posterior wall thickness (PWT), and interventricular septal thickness (IVS) were significantly higher compared to patients possessing the II and ID genotypes (P < 0.02, P < 0.003, and P < 0.009, resp.). The DD genotype exists more frequently in ADPKD patients with ESRD and is associated with a higher occurrence of LVH and disturbances in systolic-diastolic function when compared to ADPKD ESRD patients with the II and ID genotypes.

Acute Progression of Adult-Onset Atypical Hemolytic-Uremic Syndrome due to CFH Mutation: A Case Report

Atypical hemolytic-uremic syndrome (aHUS), unlike typical HUS, is not due to bacteria but rather to an idiopathic or genetic cause that promotes dysregulation of the alternative complement pathway. It leads to hemolytic anemia, thrombocytopenia, and renal impairment. Although aHUS secondary to a genetic mutation is relatively rare, when occurring due to a mutation in Factor H (CFH), it usually presents with younger onset and has a more severe course, which in the majority ends with end-stage renal failure. Paradoxically to most available data, our case features acute aHUS due to a CFH mutation with late onset (38-year-old) and rapid progression to end-stage renal disease. Due to current data indicating a high risk of graft failure in such patients, the diagnosis of aHUS secondary to a genetic cause has disqualified our patient from a living (family) donor renal transplantation and left her with no other option but to begin permanent renal replacement therapy.